Grouser for tractor wheels



VENTURO RAATTONI, OF NEAR CHNO, CALIFORNIA, A SSIGNOR OF ONE-.HALF TOJOSEPH NG-ERSOLL, OF LOS ANGELES, CALIFORNIA.

GROUSER FOR TRACTOR JVHEELS.

incense.

Application led Iiay 29,

To all 'zc/1.0m 'it muy concern.'

Be it known that l, Vnn'runo v,de-.PATTONI, a citizen of the UnitedStates, residing near Chino, in the county of San Bernardino, State ofCalifornia, have invented new and useful Improvements in Grousers forTractor lllheels, of which the following is a specilication.

This invention relates to traction devices for self-propelled vehicles,such as t actors; and the general object of the invention is theprovision of a tractor device having a good non-slipping grip upon soil,and particularly upon soft soil. lt has heretofore been difficult toprovide effective traction devices, particularly for tractors havingwheel drives, in soft or sandy soil; and a particular object of mypresent invention is to provide a traction device applicableparticularly to wheeled tractors, and adapted particularly to giveeffective and sure traction results in soft and sandy soil.

As a result of long consideration of the necessary requirements, andextended experimentations and trials, l have produced a traction deviceaWheel grouser-which gives highly efficient results in soft and sandysoil. l have determined that, in order to produce efficient tractionresults, certain conditions must be met and complied with; and thoseconditions, as well as the features of my invention, which meet andcomply with them, will be best understood from the following detaileddescription of a specific form of my invention; reference for thispurpose being had to the accompanying drawings in which- Fig. 1 is aside elevation showing a wheel equipped with my improved grousers; Fig.2 is a plan of the same; Fig. 3 is a section showing the sectionalconfiguration of one of the grousers; Fig. 1 is a bottom plan view of agrouser (showing the face of the grouser which fits against theperiphery of the wheel-)g Fig. 5 lis a rear face view of a grouser; andFigs. 6, 7 and 8 are enlarged diagrammatic sections illustrating theaction of the grousers in soft soil. in the drawings the numeral 10designates any typical tractor wheel to which l apply my grousers 11.Fig. 1 shows approximately in proper proportions, the application ofgrousers to a wheel of typical size. Although relative size is notnecessarily a restrictive feature of my invention, l illustrate thegrousers in Specification of Letters Patent.

llpatcnted Jan. 1t), 1922.

1920. Serial No. 385,297.

proper proportion, so as to give a clear idea of the practicalapplication of my invention. rElms, in Fig. 1, the grousers are shown inproper proportionate size, and in the number which l have found mostefficient, for a wheel of about 12 inch diameter.

rlhe grousers are placed diagonally across the tread face of the wheel,and where the grousers are applied to two traction wheels, they areplaced at opposite angles von the two wheels; and preferably the end ofthe grouser which first comes into contact with the soil is at theinside edge of the wheel. (Figs. 1, 6, 7 and 8 are elevations of theinside face of the wheel.)

The structural formation of each grouser is not of any particularconsequence, except as hereinafter described with relation to theground-engaging face. The diagonal ground-engaging face of the grouseris indicated by numeral 13. The grouser is so constructed as to be ofsufficient strength and sturdiness to support the contact face 13 in itsworking engagement with the soil; and for that purpose l may provide acast metal grouser of the form showln in the drawings, hollowed andribbed at its back. rllhis construction affords room for the placementof securing bolts 111, which are passed through the rim 12 of the wheeland through the Harige 15 of the grouser.

l have found, by extended erneriments and trial, that the best resultsare had in sandy soil when the angular Contact face 13 of the gro-useris placed at an angle transverse to the wheel rims as is illustrated inthe drawings. rllhis angle (as measured between thc face of the grouserand a series of radial lines through the center of the wheel) variesfrom end to end of the grouser; and this variation is such that allparts of the grouser 'face parallel to all other parts. rIhis may bebest explained by a consideration of Figures 6,7 and 8. ln Fig. 6 theedge line shown at 13a (the edge line of the contact face at the end ofthe grouser that malres rst contact with the soil) makes an angle with aradius line of about 30. The line at 13b (the edge line of the contactface at the end of the grouser that makes last contact with the soil)makes an angle with a radius line of. about 20o. But lines 132L and 13bare parallel to each. other; the contact surface of the grouser Vis aflat and unwarped surface; and thus the Contact tace oft the grouserwill make at all times and regardless of the position of the grouser,the same contact with the ground at one pointin that tace, as at anyother point. ln other words, the pressure exerted by the contact tace otthe grouser upon the soil is in the same direction upon. the soil at allpoints over its tace. To accomplish this purpose, the contact :tace willnecessarily make, at di Herent points, different angles with differentradial lines; and the dilierence between these angles with the radiallines will depend upon the angular extent ot the grouser around the^=ircumterencc ot the wheel. For" instance, `in the illustration givenin the drawing, the angle between two radii drawn one to the outer pointof line 13a and the other to the outer point oi line 18 is approximately10; and this angle is equal to the difference between the two angleswhich lines 13a and 13b makes with the respective radial lines.

By thus providing grousers with flat pressure surfaces, each grouser, as1 have said, engages and presses against the soil in the same directionat all points over its surface. Consequently, there is, -for eachgrouser, and for anyl given position for each grouser a uniform pressureagainst the soil over all of its surface, or over all of the surfacethat hap-pens at any one time to be entered. against the soil. This kindot action l find to be very elicient and, in Jfact, it obtains ellective.7, it is pressing downwardly and rearwardly against the soil in thedirection indicated by the arrow, over all or' its surface that is thenin engagement with the soil. rEhis direetiou oil' pressure is such thatthe soil will not be displaced` rearwardly and upwardly (that is, theengaged part ot the soil will not loe-dug away) but the soil will bepacked solidly behind and beneath the engaging tace ot the grouser.Movement or the soil lengthwise ot the grouser (transversely ot thewheel) is not induced by the grouser because, as hereintofore explained,the grouscr engages the soil at allpoints, and presses against the soilat all points, inthe saine direction. Consequently as the grouserproceeds .trom the position A. in Fig. 7, to position B in Fig. 8, thesoil will become packed so that as the grouser reaches position of Fig.6, positien D of Fig. 7 and position E of Fig. 8, the packed soil willafford a good abutment for the grouser to press against. And even whenthe grouser reaches its further positions and begins to be withdrawnl'from the soil, the soil has less tendency to be displaced than itwould otherwise have.

Another feature to which attention may be particularly called is this,that the angle made by the grouser face with the soil is such, in anyparticular size ot wheel and relative size or' grouser, that when thegrouser reaches such a position as indicated at F in Fig. 8 and is beingwithdrawn from the soil, its pressure tace is substantially vertical.The pressure face does not take an angle such as to have a direct. andpositive tendency to litt the soil until the grouser is practically outor the respective operative contact with the soil (see such a positionshown at Gr in Fig. 6). I

1n soft sandy soil the grousers sink into the ground to about the extentillustrated in the drawings, the wheel. tread coming down into more orless forcible contact with the soil. 1n harder soil the grousers ofcourse sink to a lesser extent into the ground. When the wheel travelsupon a hard road surface, the outer edges ot grousers fornr a more orless continuous and non-bumping support on account of their angulardisposition across the face oi' the wheel.

`While l have described my improved traction device in certain specilictorni, and have described specific angles and relative sizes anddimensions for the purpose of giving a complete understanding of theinvention, it will be readily understood that the invention is notnecessarily limited to speciic sizes, etc., and that these may be variedto suit dillferent situations, as may be included within the scope ofthe following claims. Having described a preferred form of my invention,1 claim: Y

1. ln combination with a wheel, a grouser mounted on the wheel tread andextending diagonally across the tread, the grouser having a soilengaging facewliich stands angularly to a wheel radius drawn through it;such relative angle at the endof the grouser ,first entering the soilbeing approximately thirt deo'rees and the end last enterinoc the Y D aa

